My guess was that the lengthy marriage vows -- especially when we got to hear some of them -- were a comic touch to the episode. It's so classic overthinking-Randall, and it was hilarious in spots.
And, having similarly lost myself in my first marriage (for very similar reasons), I found myself sobbing at parts of Beth's lines throughout the episode. When she said their lives wouldn't work unless she was the one doing the bending, I just about lost it. SO PERFECT for her character, and it said EXACTLY what we as viewers needed to hear to understand how she felt.
That whole fight/conversation scene in the bedroom was really well written. It wasn't trite or cheesy, wasn't stereotypical or melodramatic. It truly worked to move their story forward. Add on the odd future glimpses we've seen of Randall and his daughter in a hospital setting, and I do wonder just what becomes of those two down the road...
The show's use of flashbacks (and fast-forwards) continues to work beautifully and to flow smoothly. That's not an easy thing to do.
I too love this stupid show.
I just don't love Randall too much right now.
Oh, and yes, that mini-golf thing. WHO BRINGS THEIR MOTHER?? You'd think she could handle a "Hey, Mom, we're not coming to Sunday dinner this week" once in a while. Or does Randall just think he's honoring her by inviting her along? And WHY DID SHE GO? As a mom, I'd have said, "No, you guys go on ahead. I'm fine." What a buttinski.